Composite putter head

ABSTRACT

The golf putter head of the present invention is made of a uniform mixture of a base and a filler. The filler is chosen from materials with a high density such as metals, while the base is selected from low density materials such as plastics. The blend of the base and the filler into a uniform composite produces a putter head of unique feel and characteristics. The preferred filler for the composite is metal which adds weight and density to the total material. The metal added ranges from 50 to 95 percent by weight, depending upon the particular plastic and metal combined to achieve the desired results. The blend of metal and plastic provides a composite which is light enough to swing easily with enough weight to give a balanced feel to the putter head and furthermore, the resiliency of the material provides a good reliable response when striking a golf ball. The uniformity of the composition obviates a plastic-metal interface which can separate or mesh incorrectly leading to an inconsistent feel.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to the field of golfingequipment and more particularly to a composite golf club putter head.

[0003] 2. Description of Related Art

[0004] The game of golf has seen a dramatic rise in its popularity overthe last few years. This increase in golfs popularity has beenaccompanied by a dramatic increase in the number of golf products on themarket. Advances in technology have led to improved equipment in all ofthe sporting equipment areas, but none more so than in golf. Thesetechnological advances have led to golfing equipment which are stronger,lighter, and more durable than the equipment used by earliergenerations.

[0005] While new materials such as titanium have been used to makedriver heads, there has not been as much experimentation with newmaterials for putter heads. This is curious, since arguably one of themost important pieces of equipment in a golfer's bag is his putter. Thenumber of patents directed to golf club putters is a testament to thiscontinuing search for the ultimate putter. It is said that no other clubaffects a golfer's score more significantly than his putter because onethird to one half of an amateur's shots on a given round will be putts.Because of the individuality in putting styles and strokes, putters comein many different designs and many different shapes. Each golfer islooking for that perfect putter that has the right feel to it, inbalance, weight, and “touch.” The two most important factors whichinfluence the interaction between the ball and the putter head are theshape of the putter head and the material from which it is made.

[0006] Of primary concern to the golfer is the putter's “sweet spot.”The sweet spot denotes the area on the golf club striking surface whichproduces the optimum direction and distance for the golf ball. For mostputter heads, the sweet spot is located at or about the center of massof the golf club head, such that when the putter strikes the ball thereis no moment or torque applied to the putter which can sap energy fromthe impact with the ball. Thus all of the energy is directed to the ballfor a consistent reaction between the club and ball. Attempts toincrease the sweet spot, thereby improving the chances of hitting abetter shot, have met with varying success.

[0007] Metal is the traditional material of choice for putter heads.Thus, initial attempts to enlarge the sweet spot involved varying shapesof the putter head, and the prior art is replete with a number ofvarious putter head shapes. Various weighting techniques have also beenattempted in order to produce the optimum balance for the greatestnumber of putting styles. The traditional blade putter with its narrowhead has been followed up by the newer mallet putter, which has greaterinertia and a more solid feel to it. Several references describe putterheads with a solid, heavier member within a lighter material in anattempt to create balance and feel, while softening the impact of theputter head with the ball. See, for example, U.S. Pat. No. 5,676,606.

[0008] Other attempts to modify the putter head to soften the impactwith the golf ball, thus given the golfer more control over thedirection and speed of the ball, include U.S. Pat. No. 5,458,332 whichdescribes an interchangeable solid polyurethane insert applied to thestriking surface of the putter. U.S. Pat. No. 4,679,792 shows a putterhead with a cavity in the forward facing surface filled with a honeycombmaterial to reduce the momentum imparted on the golf ball by the putterhead. U.S. Pat. No. 3,843,122 describes a putter head with an internalcavity filled with a wooden block to absorb the energy from the impactwith the ball, causing the ball to travel slower and with more accuracy.The goal of each of these patents is to soften the normally hard impactbetween a metal surface and the golf ball by adding a material to absorbsome of the energy.

[0009] The disadvantages of the prior art are that the manufacture ofthe two discrete materials (metal with wood, honeycomb, plastic, etc.)placed adjacent to each other at an interface causes problems of itsown. Different coefficients of expansion between the two materials canlead to separation and degradation, as can sudden impact or pooradhesion. Also, the transfer of forces at the interface between the twomaterials is difficult to predict. Over time, temperature, moistureand/or stress can cause this interface to change leading to a differentfeel than the original putter feel. The present invention overcomes theshortcomings of the prior art by using a unitary composite materialwithout a plastic to metal interface to form a putter head which givesthe putter an easy, balanced swing with greatly improved touch on theball.

OBJECTS AND SUMMARY OF THE INVENTION

[0010] It is an object of the present invention to provide a golf clubputter having a head comprising a composite material of uniformconsistency having a metal uniformly blended into a plastic base withthe metal adding density to the plastic.

[0011] The composition of metal to plastic by weight is preferablybetween fifty and ninety-five percent, although the percentages may varyfrom this range depending upon the metal chosen and the plastic chosenas well as the preference of the individual golfer. The metal is blendedinto the plastic base to form a uniform composite material having uniquephysical characteristics especially suited for a golf putter head. Anon-exclusive list of plastics which may be used include ethylene vinylacetate, polyurethane, polyolefin, polypropylene, and polyvinylchloride.Although thermoplastics are the preferred type of plastic, thermosettingplastics may also be used. A non-exclusive list of metals which areeconomically practical and available include aluminum, barium, copper,iron, nickel, lead, stainless steel, and zinc.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a perspective view of a putter typical of those used inthe present invention;

[0013]FIG. 2a is an elevated view of a blade type putter head of acomposite embodying the present invention;

[0014]FIG. 2b is an elevated view of a mallet type putter head of acomposite embodying the present invention;

[0015]FIG. 3a is a cross-sectional view of the blade type putter of FIG.2a; and

[0016]FIG. 3b is a cross-sectional view of the mallet type putter ofFIG. 2b.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The following description is provided to enable any personskilled in the art to make and use the invention. It sets forth the bestmodes contemplated by the inventor of carrying out his invention.Various modifications, however, will remain readily apparent to thoseskilled in the art, since the generic principals of the presentinvention have been defined herein specifically to provide a compositeputter head made from a mixture of plastic and filler in a process forthe making thereof.

[0018]FIG. 1 illustrates a putter 10 typical of those embodying thepresent invention. The putter is comprised of a shaft 20, a grip portion30 at a first end 40, and a putter head 50 at the opposite end 60. Theshaft 20 can be made of metal or a composite material such as graphite.The grip portion 30 is typically a commercially available grip whichprovides a suitable surface for slip-resistant gripping of the putter.An optional hozel (not shown) may be used to connect the putter head tothe putter shaft as is well known in the art.

[0019] Putter heads are generally of one of two types, a blade type 50 aand a mallet type 50 b (see FIGS. 2a and 2 b, respectively). The bladetype design is the more traditional of the two designs and is generallypreferred by many of the top golfing professionals today. The malletdesign has the advantage of a better defined center of mass and gravity,and is preferred among the larger amateur group of golfers. The presentinvention is applicable to both the blade type design, the mallet typedesign, and the many variations thereof.

[0020] The golf putter head of the present invention is made of auniform mixture of a base and a filler, as can be seen in FIGS. 3a and 3b. The filler is chosen from materials with a high density such asmetals, while the base is selected from low density materials such asplastics. The blend of metal and plastic provides a composite which islight enough to swing easily with enough weight to give a balanced feelto the putter head and furthermore, the resiliency of the materialprovides a good response when striking a golf ball. The uniformity ofthe composition obviates a plastic-metal interface which can separate ormesh incorrectly leading to an inconsistent feel or shot.

[0021] The preferred filler for the composite is metal which adds weightand density to the total material. The metal added ranges from 50 to 95percent by weight, depending upon the particular plastic and metalcombined to achieve the desired results. A non-exclusive list of thetypes of metals which can be used as fillers are as follows: aluminum,barium, copper, iron, nickel, lead, stainless steel, and zinc. Anon-exclusive list of plastics which can be used in the compositeinclude ethylene vinyl acetate, polyurethane, polyolefin, polypropylene,and polyvinylchloride. Though thermal plastics are more appropriate, itdoes not preclude the use of thermal setting plastics in the presentinvention. The composite materials are combined to achieve a minimumhardness of Shore A85 for putters required to meet USGA approval.

[0022] The blending of these materials can be achieved with standardplastic blending equipment and manufacturers' recommended temperatures.The feed rates of the particular materials being blended must beselected based on the composition of metal to plastic and the types ofmetals and plastics selected, where experienced blenders can easilydetermine the correct rate. Injection molding is the most suitable forforming golf club heads of the present invention. However, anycompression type process or method of producing solid parts issatisfactory for making weighted plastic golf club heads. It is theweighted plastic that make these clubs unique.

[0023] The composite material is generated by blending mechanicallymixed dry pellets and powdered metal, and extruding the composite in aplastic extruder. The quantity of particulate filler is predeterminedbased on the weight of the base material and the weight of the filler sothat the appropriate composition by weight can be established. Theplastic-metal composition is then shaped into the putter head usingeither an injection molding process or suitable alternative shapingprocess. Once cooled and removed from the molding, the putter head canbe secured to a putter shaft of choice similar to traditional putterheads.

[0024] Those skilled in the art will appreciate that various adaptationsand modifications of the just-described preferred embodiment can beconfigured without departing from the scope and spirit of the invention.Therefore, it is to be understood that, within the scope of the appendedclaims, the invention may be practiced other than as specificallydescribed herein.

What is claimed is:
 1. A golf club putter comprising a shaft with a gripat a first end and a putter head at a second end, said putter headcomprising a composite material including a plastic base with auniformly blended metal dispersed therein, said metal comprising atleast fifty percent by weight of said composite material.
 2. The golfclub putter of claim 1 wherein said metal is selected from aluminum,barium, copper, iron, nickel, lead, stainless steel, and zinc.
 3. Thegolf club putter of claim 1 wherein said plastic base is selected fromethylene vinyl acetate, polyurethane, polyolefin, polypropylene, andpolyvinylchloride.
 4. A golf club putter head comprising a compositematerial including a plastic base with a uniformly blended metaldispersed therein, said metal comprising at least fifty percent byweight of said composite material.
 5. The golf club putter head of claim4 wherein said metal is selected from aluminum, barium, copper, iron,nickel, lead, stainless steel, and zinc.
 6. The golf club putter head ofclaim 4 wherein said plastic base is selected from ethylene vinylacetate, polyurethane, polyolefin, polypropylene, and polyvinylchloride.7. The golf club putter head of claim 4 wherein a hardness of saidputter head is at least Shore A85.
 8. The golf club putter head of claim4 wherein said plastic base is a thermal setting plastic.
 9. The golfclub putter head of claim 4 wherein a ratio of said metal filler to saidplastic base is between 50 and 95 percent by weight.